Plant food manufacture



July 20, 1937.

o. w. RANDQLPH PLANT FOOD MANUFACTURE Filed Aug. l,` 1951 3 Sheets-Sheetl O. W. RANDOLPH PLANT FOOD MANUFACTURE July 20, 1937.

Filed Aug. l, 1931 3 Sheets-Sheetl 2 July 20, 1937.

Filed Aug. l, 1931 5 Sheets-Sheet gru/nudo@ Patented July 20,v 1937 juNrrEnV STATES PATENT OFFICE PLANT Poop MANUFACTURE @liver Randolph,Toledo, Ohio Application August 1, 1931, seriarNo. 554,415

9 claims. `ucl. :i4-12) 'Ihis invention relates to treating material,more especially for the removal of moisture therefrom.

This invention has utility when incorporated in handling sewage sludge,more particularly for the production of fertilizers for the turf orgreens of golf courses,

Referring to the drawings:

Fig. 1 is a plan view of an embodiment of the invention for effectingdrying of sewage sludge into agricultural fertilizer materials;

Fig. 2 is a fragmentary side elevation, on an enlarged scale of feederand perforator features of the installation of Fig. 1;

Fig. 3 is a fragmentary side elevation of the drier portion of theinstallation of Fig. 1;

Fig. 4 is a, section on the line IV-IV, Fig. 3;

Fig. 5 is a fragmentary elevation, from the right of Fig. 1, showingfeatures of the drying medium Supply;

Fig. 6 is a fragmentary elevation of the peat drier and its assemblyconnections in the installation; and

Fig. 7 is a detail view in plan of a layer fragment of the material andits support for passage thru the drier proper.

l Furnace I may be of the hot air type, along the lines of thedisclosure in U. S. Patent 1,685,339,

to O. W. Randolph, Sept. 25, 1928. Fuel may be supplied by stoker 2. Thedrying medium, which 'may include warmed air as' well as the gases fromthe products of combustion, may pass by duct 3 to be drawn into chamber4, and there forced by fan 5 into spread delivery way 6. The fan 5 isdriven by motor 'L Draft into the furnace I is pro; .oted by fan 5 (Fig.l).

The way 6 extends to housing 8 having entrance ports (Fig. 4) oropenings 9 to chambers IIJ in communication with chambers II from whichexit ports or openings I2 may discharge the gaseous medium as more orless chilled and with an acquired volatile or moisture portion. Thesegases may be allowed to escape, or be conserved by eiectingstage reuse,if not in the housing 8,

by conducting such, or a portionthereof through duct I3.

Duct I3 is in communication with duct I4 from the furnace I as abranchor separate from the delivery to the way 6 (Fig. 1).. Damper I5 may beadjusted for mixing of gases or selection of either for delivery to peatdrier housing I6. Hopper I1 is in communication with a supply of peat,more or less coarse, which as air dried, may carry quite a moisturecontent.

of plows 25.

clear water portions.

subdivided peat is thus delivered into the upper portion of the housingI6 to fall upon deck 2|. Motor 22 is connected by speed reductiongearing 23 for slowlyvrotating shaft 24, having thereon at differentdeck regions, a plurality of radial series 5 These plows are (Fig. 6) sodisposed as to progress material from the deck 2l to fall thru opening26 near the outer portion of the deck to be received by next lower deck21, there urged by the plows toward the shaft v24 to 10 fall thruopening 28 for a repetition of the cycle at 'a succeeding deck 2l.During this travel of the ground peat, the drying medium passing thedamper I5 flows upward across the several decks to remove moisture fromthe peat, and then passes 15 from this drier by way of stack 29. Beltgearing 30 operates conveyor 3l (Fig. 6) for removing the dried peatfrom the drier'and conducting this peat 32 to mixing conveyor 33.

Sewage disposal plants, especially for munici- 20 palities, are makingefforts to separate the solid carrying portions of the sewage, which arerich inmaterials suitable for agricultural fertilizer purposes.

This sewage substance or waste, currently 25 termed sludge, is separatedfrom the relatively The clear water portions are so handled that suchmay be returned, say to streams or bodies of water, with pollutiondangers practically eliminated, or so reduced as 30 to cause no serioushazard. The sludge is not responsive to water removal in an economicalmanner directly to give the sludge commercial worth competitively in dryagricultural fertilizer fields. Wherev the sludge may be hauled intanks, 35 and there is no objection to the odors therefrom, when dumpedin the fields, it has fertilizer value. This greatly limits' the use ofthese valuable soil enriching properties.

Such sludge is readily pumped about at the 40 sewage disposal plant,andsupply line 34 has valve 35 adjustable to regulate the flow of suchsludge into the mixing conveyor 33. This mingling with ground dried peatis in such proportion of the peat as to produce a paste, which may be 45of the consistency of a thin putty. The peat need not be added to aproportion to give the sludge a heavy thick body. However, as a minimum,it should be added so to hold the mass 5'0 that it may be spread into alayer, at least without materially running therefrom. Motor 36 t drivesthis mixing conveyor, which delivers to conveyor 31 serving as anelevator driven by motor 38 to discharge the paste material into hopper39. 55

This hopper 39 has lower discharge port 49. The gearing 39 is drivenfrom the motor 3E.

Motor 4| is effective thru sprocket chain 42 to drive wheel 43 on shaft44 located below the housing 8. Sprocket wheel 45 on the shaft 44 isconnected by sprocket chain 46 with sprocket wheel 41 on shaft 48 abovethe housing 8 (Fig. 3). Sprocket wheels 49 on the shaft 48 have sprocketchains 59 extending to sprocket wheels 5i on shafts 52, 53, 54, 55,located above the ports 9. Shafts 55, 51, 58, 59, are located below theports I2. The shaft 84 carries gear wheel 69 in mesh with gear wheel 92on the shaft 58.

The shaft 54 has thereon drum 63 for mesh wire belt 54 (Fig. 3)extending to drum 65 on shaft 98 mounted by the frame 91 (Fig. 2) tohave a reach of this flem'ble linkage belt 64 pass below the dischargeport 49 of the hopper 39, there to receive flow of paste 6B, hereindisclosed as sewage sludge thickened` with ground dried peat, which peathas constituents not objectionable, and in some instances desirable fora soil fertilizer.

It is desirable to have the paste maintain its i position with the belt55 so that the belt travel directions may be changed and the region fortreatment be localized. Pivot bearings 69 for leaves or plates 19havingadjustable weights 1I, provide spreader means for compacting thesludge-peat mass 58 into a layer 12. This beltheldmass 98 has more orless continuity. To increase its susceptibility to drying action, it hasbeen found advantages follow from use ofthe treating medium foreffecting such drying, thru the mass. Treatment to render the massporous or perforate is undertaken. In carrying this out mechanically,sprocket wheel 13 on the shaft 59 has sprocket chain 15 to sprocketwheel 15 on shaft 15. Sprocket wheel 11 also on the shaft 16 has chain18 therefrom to sprocket wheel 19 on shaft (Fig. 3). This shaft 89 hasthereon cam 8i (Fig. 2) acting on lever 82 having fulcrum 83. Remotefrom the cam 8|, the lever 82 is connected to bar 84 having plate 85from which depend a plurality of relatively loose pins 86. Rotation ofthe shaft 80 during the travel of the belt 64, causes the plate 85 tobob up and down and the pins 86 to be thrust thru the mesh openings inthe belt 64 to make perforations 81 thru the layers 12.

The layer is now ready for treatment by the- 9. The perforations 81 inthe layer 12 of the sludge-peat paste mass serve as ports for the flowof the medium from the chambers I0 into the chambers Il in the housing 8betweendownwardly traveling reaches 90 and upwardly traveling reaches89. From these chambers Il the medium having taken on volatiles from thelayer 12 toward drying out such mass, may have exit at the ports I2. Inpractice these reaches 89, 90, may be fifteen to twenty feet long. Thespiral wire mesh belt 64 may be four feet wide. The number of reaches,and consequently the length of the belt, may var'y with the capacitydesired and the lineal travel rate adopted for the belt. Atmosphericconditions may be a minor factor The dried product from the housing 8 islargely still retained by the belt 94. Sprocket wheel 9i on the shaft 44has sprocket chain 92 extending to sprocket wheel 93 (Fig. 3) on shaft94. Sprocket wheel 95 on the shaft 94 has sprocket chain 96 therefrom tosprocket wheel 91 on shaft 98. On the shaft 94 is rotary brush 99 forthelower side of the belt 64, while on the shaft 98 is rotary brush 99 forthe upper side of the belt 64. There is thus effected positive removalof the dried substance |00 as a subdivided mass into collecting chamberor hopper lill in` a condition suitable for sacking, or other packagingfor indenite postponement of later use. Even from sewage waste, thisproduct does not carry objectionable odors, and so may be used, even inthe playing season, as a turf food on golf courses and on the lawns ofprivate estates. The deodorizing is promoted by the combustion fumesfrom the furnace which may include some sulfur.

What is claimed and it is desired to secure by Letters Patent is:

1. The method of reducing the moisture content of paste materialcomprising forming the material into a sheet-like layer, perforatingsaid layer by means reciprocating transversely of the layer whileretaining the layer in its sheet-like form and circulating a dryingmedium about the layer and through the perforations.

2. The method of producing plant food-in dry form comprising mixingground peat with sewage sludge to form paste material, forming themateis retained in its sheet-like form, and subjecting one side of thelayer to incoming forced draft to pass through such layer.

3. A sewage sludge handling installation embodying foraminous conveyormeans, a feeder device thereto to form supply material into a sheetlikelayer on the conveyor means, perforating means for the layer, anactuator for reciprocating the perforating means directly through thelayer While the layer is adherent to the conveyor means, and means forowing a drying medium through the perforations of the layer after theperforating means are withdrawn to effect draft through the perforationsinthe layer and the openings of the conveyor means registeringtherewith.

4. An agricultural fertilizer installation embodying a foraminousconveyor for a paste material, means for spreading the material on theconveyor into layer form, means for creating openings through the spreadmaterial in registry with the openings in the conveyor, said layer llayer while retaining the layer in its sheet-like lform, placing thelayer to act as a perforate diaphragm, and circulating a drying mediumthrough the perforations of said` diaphragm.

7. The method of drying comprising forming paste material into ahorizontally extending sheet-like layer, vertically perforatingthe layerwhile the layer is retained in its sheet-like form, progressing saidlayer as a perforate diaphragm, subjecting one side of the perforatediaphragm to incoming forced draft, and conducting exhaust from theother side of the diaphragm in promoting drying draft through thepertorate diaphragm.

8. A sewage sludge handling installation embodying conveyor means havingopenings therethrough, a feeder device thereto to form supply materialinto a sheet-like layer on the conveyor means, periorating means forthelayer adjacent the device, -an actuator for operating the perforatingmeans to pierce directly into the layer and through said openings-in theconveyor means, and housing means for the conveyor means spaced from thedevice for flowing a drying medium through the perforations of the layeras maintained by the conveyor means in sheet-like form after theperforating means are withdrawn,

thereby to effect draft through the conveyor means openings and theperforations oi the layer.

4 9. A drier installation embodying a conveyor yfor paste material, saidconveyor having openings therethrough, means for spreading the materialon the conveyor into layer form, means for creating'openings through thespread material and at the openings in the conveyor, said layer beingcarried therefrom bythe conveyor in maintained sheet-like form, and gassupply and conducting means for owing gas through the openings in theconveyor and material.

v OLIVER W.

